Senescence can play an essential role in modelling and estimation of vector based epidemiological indicators: demographical approach

In the paper basic epidemiological indicators, produced by an aging population of vectors, are calculated. In the study we follow two lines: calculations for demographically structured population and individual life-history approach. We discuss the advantages and limitations of these approaches and compare the results of our calculations with epidemiological indicators obtained for non-aging population of vectors.Gibraltar, age effect, disease control, gerontology

An organotypic slice culture to study the formation of calyx of Held synapses in-vitro.

The calyx of Held, a large axo-somatic relay synapse containing hundreds of presynaptic active zones, is possibly the largest nerve terminal in the mammalian CNS. Studying its initial growth in-vitro might provide insights into the specification of synaptic connection size in the developing brain. However, attempts to maintain calyces of Held in organotypic cultures have not been fruitful in past studies. Here, we describe an organotypic slice culture method in which calyces of Held form in-vitro. We made coronal brainstem slices with an optimized slice angle using newborn mice in which calyces have not yet formed; the presynaptic bushy cells were genetically labeled using the Math5 promoter. After six to nine days of culturing, we readily observed large Math5-positive nerve terminals in the medial nucleus of the trapezoid body (MNTB), but not in the neighboring lateral superior olive nucleus (LSO). These calyx-like synapses expressed the Ca2+- sensor Synaptotagmin-2 (Syt-2) and the Ca2+ binding protein Parvalbumin (PV), two markers of developing calyces of Held in vivo. Application of the BMP inhibitor LDN-193189 significantly inhibited the growth of calyx synapses, demonstrating the feasibility of long-term pharmacological manipulation using this organotypic culture method. These experiments provide a method for organotypic culturing of calyces of Held, and show that the formation of calyx-like synapses onto MNTB neurons can be preserved in-vitro. Furthermore, our study adds pharmacological evidence for a role of BMP-signaling in the formation of large calyx of Held synapses

Discovering predictive variables when evolving cognitive models

A non-dominated sorting genetic algorithm is used to evolve models of learning from different theories for multiple tasks. Correlation analysis is performed to identify parameters which affect performance on specific tasks; these are the predictive variables. Mutation is biased so that changes to parameter values tend to preserve values within the population's current range. Experimental results show that optimal models are evolved, and also that uncovering predictive variables is beneficial in improving the rate of convergence

Stress-related anhedonia is associated with ventral striatum reactivity to reward and transdiagnostic psychiatric symptomatology

BACKGROUND: Early life stress (ELS) is consistently associated with increased risk for subsequent psychopathology. Individual differences in neural response to reward may confer vulnerability to stress-related psychopathology. Using data from the ongoing Duke Neurogenetics Study, the present study examined whether reward-related ventral striatum (VS) reactivity moderates the relationship between retrospectively reported ELS and anhedonic symptomatology. We further assessed whether individual differences in reward-related VS reactivity were associated with other depressive symptoms and problematic alcohol use via stress-related anhedonic symptoms and substance use-associated coping. METHOD: Blood oxygen level-dependent functional magnetic resonance imaging (fMRI) was collected while participants (n = 906) completed a card-guessing task, which robustly elicits VS reactivity. ELS, anhedonic symptoms, other depressive symptoms, coping behavior, and alcohol use behavior were assessed with self-report questionnaires. Linear regressions were run to examine whether VS reactivity moderated the relationship between ELS and anhedonic symptoms. Structural equation models examined whether this moderation was indirectly associated with other depression symptoms and problematic alcohol use through its association with anhedonia. RESULTS: Analyses of data from 820 participants passing quality control procedures revealed that the VS × ELS interaction was associated with anhedonic symptoms (p = 0.011). Moreover, structural equation models indirectly linked this interaction to non-anhedonic depression symptoms and problematic alcohol use through anhedonic symptoms and substance-related coping. CONCLUSIONS: These findings suggest that reduced VS reactivity to reward is associated with increased risk for anhedonia in individuals exposed to ELS. Such stress-related anhedonia is further associated with other depressive symptoms and problematic alcohol use through substance-related coping

Non-contact infrared temperature measurements in dry permafrost boreholes

While planning the COAST Expedition to the Siberian Laptev Sea in 2005, the question of how to make a short equilibrium temperature measurement in a dry borehole arose. As a result, an infrared borehole tool was developed and used in three dry boreholes (up to 60.2 m deep) in the coastal transition zone from terrestrial to sub-sea permafrost near Mamontovy Klyk in the western Laptev Sea. A depth versus temperature profile was acquired with equilibration times of 50 × 10−3 s at each depth interval. Comparison with a common resistor string revealed an offset due to limitations of accuracy of the infrared technique and the influence of the probe's massive steel housing. Therefore it was necessary to calibrate the infrared sensor with a high precision temperature logger in each borehole. The results of the temperature measurements show a highly dynamic transition zone with temperature gradients up to −0.092°C/m and heat flow of −218 mW/m. A period of submergence of only 600 years the drilled sub-sea permafrost is approaching the overlying seawater temperature at −1.61°C with a temperature gradient of 0.021°C/m and heat flow of 49 mW/m. Further offshore, 11 km from the coastline, a temperature gradient of 0.006°C/m and heat flow of 14 mW/m occur. Thus the sub-sea permafrost in the Mamontovy Klyk region has reached a critical temperature for the presence of interstitial ice. The aim of this article is to give a brief feasibility study of infrared downhole temperature measurements and to present experiences and results of its successful application

The O(N) linear sigma model at finite temperature beyond the Hartree approximation

We study the O(N) linear sigma model with spontaneous symmetry breaking, using a Hartree-like ansatz with a classical field and variational masses. We go beyond the Hartree approximation by including the two-loop contribution, the sunset diagram, using the 2PPI expansion. We have computed numerically the effective potential at finite temperature. We find a phase transition of second order, while it is first order in the Hartree approximation. We also discuss some implications of the fact that in this order, the decay of the sigma into two pions affects the thermal diagrams.Comment: 22 pages, 14 figures. v2: minor corrections, some more references. v3: added new set of data, new appendix. Submitted to Phys.Rev.

Markedly Divergent Tree Assemblage Responses to Tropical Forest Loss and Fragmentation across a Strong Seasonality Gradient

We examine the effects of forest fragmentation on the structure and composition of tree assemblages within three seasonal and aseasonal forest types of southern Brazil, including evergreen, Araucaria, and deciduous forests. We sampled three southernmost Atlantic Forest landscapes, including the largest continuous forest protected areas within each forest type. Tree assemblages in each forest type were sampled within 10 plots of 0.1 ha in both continuous forests and 10 adjacent forest fragments. All trees within each plot were assigned to trait categories describing their regeneration strategy, vertical stratification, seed-dispersal mode, seed size, and wood density. We detected differences among both forest types and landscape contexts in terms of overall tree species richness, and the density and species richness of different functional groups in terms of regeneration strategy, seed dispersal mode and woody density. Overall, evergreen forest fragments exhibited the largest deviations from continuous forest plots in assemblage structure. Evergreen, Araucaria and deciduous forests diverge in the functional composition of tree floras, particularly in relation to regeneration strategy and stress tolerance. By supporting a more diversified light-demanding and stress-tolerant flora with reduced richness and abundance of shade-tolerant, old-growth species, both deciduous and Araucaria forest tree assemblages are more intrinsically resilient to contemporary human-disturbances, including fragmentation-induced edge effects, in terms of species erosion and functional shifts. We suggest that these intrinsic differences in the direction and magnitude of responses to changes in landscape structure between forest types should guide a wide range of conservation strategies in restoring fragmented tropical forest landscapes worldwide

On the Hidden Order in URu2_{2}Si2_{2} --- Antiferro Hexadecapole Order and its Consequences

An antiferro ordering of an electric hexadecapole moment is discussed as a promising candidate for the long standing mystery of the hidden order phase in URu$_{2}$Si$_{2}$. Based on localized $f$-electron picture, we discuss the rationale of the selected multipole and the consequences of the antiferro hexadecapole order of $xy(x^{2}-y^{2})$ symmetry. The mean-field solutions and the collective excitations from them explain reasonably significant experimental observations: the strong anisotropy in the magnetic susceptibility, characteristic behavior of pressure versus magnetic field or temperature phase diagrams, disappearance of inelastic neutron-scattering intensity out of the hidden order phase, and insensitiveness of the NQR frequency at Ru-sites upon ordering. A consistency with the strong anisotropy in the magnetic responses excludes all the multipoles in two-dimensional representations, such as $(O_{yz},O_{zx})$. The expected azimuthal angle dependences of the resonant X-ray scattering amplitude are given. The $(x^{2}-y^{2})$-type antiferro quadrupole should be induced by an in-plane magnetic field along $[110]$, which is reflected in the thermal expansion and the elastic constant of the transverse $(c_{11}-c_{12})/2$ mode. The $(x^{2}-y^{2})$-type [$(xy)$-type] antiferro quadrupole is also induced by applying the uniaxial stress along $[110]$ direction [$[100]$ direction]. A detection of these induced antiferro quadrupoles under the in-plane magnetic field or the uniaxial stress using the resonant X-ray scattering provides a direct redundant test for the proposed order parameter.Comment: 10 pages, 10 figures, 5 table

Otoferlin acts as a Ca2+ sensor for vesicle fusion and vesicle pool replenishment at auditory hair cell ribbon synapses

Hearing relies on rapid, temporally precise, and sustained neurotransmitter release at the ribbon synapses of sensory cells, the inner hair cells (IHCs). This process requires otoferlin, a six C2-domain, Ca2+-binding transmembrane protein of synaptic vesicles. To decipher the role of otoferlin in the synaptic vesicle cycle, we produced knock-in mice (Otof Ala515,Ala517/Ala515,Ala517) with lower Ca2+-binding affinity of the C2C domain. The IHC ribbon synapse structure, synaptic Ca2+ currents, and otoferlin distribution were unaffected in these mutant mice, but auditory brainstem response wave-I amplitude was reduced. Lower Ca2+ sensitivity and delay of the fast and sustained components of synaptic exocytosis were revealed by membrane capacitance measurement upon modulations of intracellular Ca2+ concentration, by varying Ca2+ influx through voltage-gated Ca2+-channels or Ca2+ uncaging. Otoferlin thus functions as a Ca2+ sensor, setting the rates of primed vesicle fusion with the presynaptic plasma membrane and synaptic vesicle pool replenishment in the IHC active zone